As semiconductor devices scale to smaller dimensions, the ability to avoid defects in device structures becomes more challenging. For example, the synthesis of three-dimensional semiconductor transistors, such as fin type field effect transistors (finFET), involves many deposition and etch operations to define a gate structure and source/drain (S/D) region of a transistor. Several of these operations may involve etchants exposing isolation structures, such as a shallow trench isolation (STI) layer, to undue etching. In some cases, the etching of the STI layer may be sufficient to undercut device structures, such as gate structures, causing gate bending or other defects, where such defects may degrade or destroy device performance.
With respect to these and other considerations, the present disclosure is provided.